Abstract: Vessel provided with at least one water jet propulsion unit consisting of a casing containing, between an intake (3) tangential to the hull (2) and a rear water outlet (4), a duct (5) upstream of the propulsion device, an impeller (6), fixed flow-correction guide vanes (7) and a tail cone (8) carried by the blades which with the casing (9) form the tail pipe (10). The cross section of the tail pipe (10) varies but within narrow limits between the vanes (7) and the outlet (4) by virtue of a number of gas injection slots situated in the area of the trailing edges of the vanes (7) and connected by a circuit to a supply of compressed gas (16). The gas supply circuit includes an external annular chamber (14) formed within the casing and the shroud surrounding the vanes (7) and connected to the injection slots (25, 26, 29). Of application to vessels requiring very high thrusts.

Abstract: The purpose of the invention is a cross flow fan comprising an convergent inlet (2,3,10), an impeller (1) or rotor provided with blades and a divergent (4) delimited by a downstream face (12) of the scroll element and a downstream face (9) of the cross-head element. The inlet and divergent delimit two narrowing longitudinal passages (13, 14). With respect to a reference system of perpendicular axes x and y, the origin of which is located on the axis of rotation of the impeller (1) and whose abscissa X axis is parallel to the downstream face (9) of the cross-head element, it features:an upstream leading edge (6) of the cross-head element describing an angle included between 290.degree. and 330.degree. at a distance from the impeller or an air gap (13) included between 2 and 8% of the outside diameter De of the impeller,a face (7) of the cross-head element describing an angle, the apex of which is one and the same with upstream leading edge (6) of the cross-head, included between -20.degree. and 60.degree.

Abstract: The present invention concerns hull shapes for a surface effect ship, including a catamaran type supported structure with two side walls (100) connected by a center platform (200), able to operate either as a buoyant displacement vehicle, or as an air cushion supported vehicle, the side walls (100) confining, with two sealing devices (310, 320), the supporting center air cushion (c).